In conventional liquid-crystal displays (TN, STN, OMI or AMD-TN), the electric fields for realignment are generated essentially perpendicular to the liquid-crystal layer.
International Patent Application WO 91/10936 discloses a liquid-crystal display in which the electric signals are generated in such a way that the electric fields have a significant component parallel to the liquid-crystal layer (IPS, in-plane switching). The principles of operating such a display are described, for example, by R. A. Soref in Journal of Applied Physics, vol. 45, No. 12, pp. 5466-5468 (1974).
EP 0 588 568 discloses various ways of addressing a display of this type.
These IPS displays can be operated with liquid-crystalline materials either of positive or of negative dielectric anisotropy (.DELTA..epsilon..noteq.0). However, using the materials known hitherto, relatively high threshold voltages and long response times are reached in IPS displays. In addition, the problem of crystallization of the liquid-crystal medium at low temperatures can occur in IPS displays containing materials known hitherto. The object was therefore to indicate liquid-crystalline materials which are suitable for achieving relatively low threshold voltages and short response times in IPS displays and which, in particular, have an improved low-temperature shelf life.